def reduce_one_heading_hash(line):
    stripped = line.lstrip()
    count = 0
    for char in stripped:
        if char == '#':
            count += 1
        else:
            break
    # 保证至少保留一个 #
    new_count = max(1, count - 1)
    content = stripped[count:].lstrip()
    return f"{'#' * new_count} {content}"

# 示例
line = "###### 标题内容"
new_line = reduce_one_heading_hash(line)
print(new_line)
